Two teams of researchers from the University of Maryland and Harvard have built quantum computers that can manipulate matter bits.

The results, which have been published in the journal Nature, show the capabilities of two quantum simulators, which are much faster than existing conventional or quantum computers. The research represents one of the largest quantum bits’ array, referred to as qubits, which could be individually controlled.

A New Quantum Simulator

The physicists produced a 51-atom chain and made them go through a transition of quantum phase in which every other atom in the array was excited in a pattern similar to an antiferromagnet. It is a state of magnetism in which every other molecule’s or atom’s spin is in alignment.

The array of 51 atoms was not really a typical quantum computer but a quantum simulator, which is a system of computer bits that can be created to mimic a particular problem or work out a specific equation. It is much quicker than the fastest conventional computer.

The new quantum simulator can reconfigure atoms’ patterns and observe new matter states and entanglement, which is a quantum phenomenon. It can also be the root for unraveling optimization problems such as the traveling salesman problem. The problem is related to the shortest route a salesman must take to cover a certain set of cities.

"This problem is exponentially hard for a classical computer, meaning it could solve this for a certain number of cities, but if I wanted to add more cities, it would get much harder, very quickly," said Vladan Vuleti, coauthor of the study.

The researcher also added that there is no need for a quantum computer for this type of a problem because a simulator can be used to mimic the right system. Therefore, the research team thinks that optimization algorithms are the clearest problems to work out on.

Quantum Computers vs Conventional Computers

Quantum computers are mostly theoretical equipment that has the potential to solve even the most intricate calculations in a fraction of time taken by the most efficient traditional computer in the world. They solve problems with the help of qubits that, unlike a classic computer’s binary bits, can be in a 0 and 1 position simultaneously.

The superposition quantum property enables one qubit to conduct two different streams of calculations, while extra qubits in a system can speed up the calculations in an exponential way. There have, however, been problems that have prevented researchers from realizing quantum computer that is fully operational, such as how to make one qubit interact with another while not interacting with the environment surrounding them. Vuleti and his team solved this problem by using neutral atoms as qubits.

Currently, researchers are planning to test the 51-atom system as a quantum simulator for problems related to path-planning optimization that can be worked out with the help of adiabatic quantum computing.